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Maintaining Tropical and Coldwater Aquarium Fishes
Aquarium Selection
There are a number of points to consider when deciding what size aquarium to purchase. The potential size of the fish you want to keep, the type of fish you want, and how many you would like to have. It is also important to make sure you have enough space for the tank, any equipment, and for working around it. We recommend that you purchase as big a tank as possible as larger tanks provide a more stable environment for the fish. This is because they are less prone to temperature fluctuation (which is not good for the fish), they provide more room for the fish to behave normally, they allow the construction of hiding places, they can accommodate shoals of smaller fish (which means happier fish), and they dilute toxins more effectively during the early stages of setting up the tank. When buying a tank you have the option of either purchasing a standard glass aquarium, or a complete aquarium set-up. If buying a standard aquarium you will also need to purchase all equipment, a hood and cover tray, as well as a polystyrene sheet to put under the tank in order to provide an even surface. A complete set-up such as a AquaOne, Juwel or other system, comes with everything you need including equipment for filtering, lighting and heating the aquarium.
Equipment
Filter
The filter is the most important piece of equipment in the aquarium. It keeps the water free of pollutants which would otherwise kill your fish. Although there are many different designs of filter and filtration media, there are three main types of filtration relevant to the aquarium.
1. Mechanical Filtration:Mechanical filters and filter media serve to remove any solid waste from the aquarium, this usually originates from uneaten fish food, fish faeces, and broken bits of plant etc. If not removed from the aquarium, this will break down, producing toxic ammonia, using up oxygen, clogging the biological filter, creating murky water, acting as a site for disease causing organisms to multiply, and in some cases physically damaging the fish. Mechanical filtration media (such as sponges) should be regularly cleaned, in order to remove waste from the tank and allow the correct functioning of the biological filter. Water should pass through the mechanical media before it enters the rest of the filter.
2. Biological Filtration:Biological filter media is designed to provide a large surface area onto which specific types of bacteria can attach and multiply. These bacteria are called “nitrifiers” and they covert toxic ammonia into nitrite, and nitrite into virtually harmless nitrate. Ammonia is produced in the tank by the fish and also through the breakdown of organic matter. Without a biological filter ammonia would quickly build up in the tank resulting in fish deaths and outbreaks of disease.
3. Chemical Filtration.“Chemical” filtration media comes in a variety of forms and is used to complement or in some cases replace the biological filter. It is usually the last stage of the filtration process and is used to “polish” the water before it is returned to the aquarium. For example, activated carbon absorbs colours, pollutants and organic wastes from the aquarium, resulting in cleaner tank water. Certain rocks (called ion-exchange resins) have the ability to remove ammonia’s and other components from the water and can therefore replace the biological filter. Products such as Rena Bio-Chem Zorb combine the properties of carbon and ion-exchange resins to provide more comprehensive filtration. Other media’s available include those designed to soften the water and remove nitrates and phosphates (resulting in less algal growth). Most of the chemical media’s require recharging or replacing on a regular basis, and those such as carbon need to be removed if treatments are being added to the tank.
Sizing a filter for your tank is relatively easy as the products we sell state what size tank or what volume of water they will filter. Working out the volume of your tank can be done with the following equations:
IMPERIAL (Length x Width x Depth in inches) x 6.23 = Gallons
METRIC (Length x Width x Depth in metres) x 1000 = Litres
The filter should be running 24 hours a day all year round. Turning the filter off for any length of time will not only allow the build up of toxic substances in the tank, but will also result in the nitrifying bacteria dying off. If the filter contains separate types of media then the mechanical part should be rinsed thoroughly on a regular basis (often the floe from the filter will cut down when it starts to become blocked). The biological part should be left untouched for as long as is possible. If it does need cleaning (i.e.if it is getting solid waste in it) the it should be removed and stirred in a bucket of water from the tank. Running this media under the tap will kill the bacteria and result in severe water quality problems. If the biological media needs changing then it should be done in stages, only changing a third at a time and leaving a gap of a few weeks between renewing each part.. In certain filters there may only be one type of media that is acting as both a biological and mechanical filter. This media should be treated as biological media and should only be cleaned in water from the tank. Chemical filter media must be replaced or recharged according to the manufacturer’s instructions.
There are three principal designs of filter available:
1. Undergravel: This is the simplest type of filter, consisting of a plastic tray lying underneath the gravel onto which an uplift tube is attached. An air line is fed into this tube and bubbles are blown into it, causing water to be drawn down through the gravel, under the tray, and up the tube. The gravel is therefore functioning as both a mechanical and biological filter. These filters are not particularly efficient, and are best suited to lightly stocked tanks, or tanks that contain fish which do not like fast currents. Because they are driven by an air pump or power head, they are good at aerating the tank.
2. Internal: Internal filters sit within the tank and operate by drawing water up through the filter media and blowing it out again. Many of the modekls available rely on a single sponge to act as a mechanical and biological filter, although some (AquaOne L series or Fluval ) have separate compartments for different medias. Internal filters usually provide the tank with good aeration as they circulate the water well, disturb the water’s surface, and some even blow bubbles into the tank.
3. External: External filters (such as Rena and Fluval range) are the most efficient and reliable type, principally because they are large and therefore can contain several different types of media. They sit outside of the tank and water is fed to them from an outlet pipe, and pumped back into the tank from the filter through a spray bar. Because of this they also take up less space in the tank and are therefore less visible. As long as the spray bar is positioned above the surface of the water they are also very good at aerating the water and providing a current within the tank. We recommend that if possible you should fit an external filter to the tank, especially if you plan to stock the tank with larger fish or with its maximum amounts of fish.
Heater
If you are planning to keep tropical fish then you will need a good heater with a thermostat control to keep the temperature constant. Different types of fish come from areas with differing temperatures, but a general community tank should be within the range of 24 – 28 degrees celcius (75 – 82 degreees fahrenheit). It is also a good idea to buy a heater guard to prevent the fish burning themselves. The size of heater needed will depend on the size of tank and to some extent on the temperature around the tank.
Light
Lighting the tank brings out the colours in the fish, and it is essential for tanks containing live plants. Different plants require different light intensities, and most need light from the blue and orange-red part of the spectrum. Different fluorescent tubes produce light of different qualities, and so it is necessary to select the one most suited to your needs. For instance, a Hagen Aquaglow bulb will encourage plant growth and bring out fish colours, whereas a Triton Blue Moon will encourage nocturnal and shy fish to come out from hiding where they can be seen. When purchasing a light, it is necessary to buy a control box which matches the wattage of the bulb. A light reflector is also beneficial, as it can greatly increase the amount of light entering the tank.
Aerator
If your aquarium has little water movement or if you are using a filter that does not aerate the water, it may be necessary to install an air-pump in order to provide enough oxygen for the tank. Even in tanks with good water movement an additional air-pump will increase the oxygen content of the water resulting in healthier, faster growing fish and a more efficient biological filter. Air-pumps, such as the Rena-Air and Tetratec Whisper range, come in a variety of sizes which can be easily matched to the size of your tank. In addition to the pump itself you will also require some air-line, a check valve to prevent water back siphoning into the pump, and a diffuser (a device that the air is blown through in order to break it up into a curtain of small bubbles).
Setting up and Starting the Aquarium
Position
The tank should ideally be placed in a quiet area, out of direct sunlight and away from heat or cold sources. Too much noise will stress the fish, as will constant changes in temperature, and direct sunlight will encourage the growth of algae.
Decoration
When decorating the tank you should try to ensure that there are places for the fish to hide and that these constructions can be removed easily to allow regular cleaning. If these constructions are to be made out of stone then it may be advisable to silicone them together to prevent them from collapsing and breaking the glass. The base of the aquarium can be covered with a range of gravel’s and sands, but it is important that these are bought from an aquatic’s outlet where they are known to be safe.
In tanks using under gravel filters then the gravel should be around 1.5 to 2 inches thick, otherwise a layer of around 0.5 to 1 inch thick is preferable as it will be easier to keep clean. Live plants can be grown in the aquarium and they may be beneficial as they may use up nitrate and phosphate, which would otherwise promote the growth of algae. However, certain fish may eat live plants, and it may also be necessary to add fertiliser (such as A.P.I.Root Tabs and Leaf Zone) to the tank, in order to keep them healthy. A good quality fluorescent tube is also essential for vigorous plant growth. An alternative is the use of artificial plants, many of which look surprisingly realistic (many of the plants in our display tank are artificial). Finally, a covering the back of the tank with some decorative backing material can add to the depth of the tank, and its overall appearance. Attaching the backing inside the tank, with some background stickers will improve the appearance, as it will seem much brighter.
Maturation
A new tank with no fish in it has to go through a process termed “maturation” before it is a fully functional aquarium. It is in fact the biological filter that is maturing, rather than the tank itself, and by maturing we mean that the filter must develop a healthy population of nitrifying bacteria before it will efficiently remove the ammonia that the fish are producing. In order to mature the filter without causing severe water quality problems the following guidelines must be followed. The tank should be set up and left to run for a few days (to allow the temperature to stabilise and any chlorine to dissipate). On the day of the first fish purchase a filter “inoculant” should be added, (such as Stress Zyme), this is a culture of live bacteria that is added to the tank in order to speed up the maturation process. Then just a few fish should be floated in their bag on the surface of the water for around twenty five minutes to allow them to acclimate to the temperature of your tank (the light should be turned off while you are doping this). Once released, the fish should be carefully watched over the following week. It is advisable to carry out partial water changes at least twice a week at this stage, and the water should be tested regularly (ideally every day) for ammonia and nitrite. If the levels of ammonia and nitrite start to rise, then a water change should be done immediately. Once the water quality has stabilised (approximately after a week or so) then a few more fish may be added, and the process repeated. The maturation process may take several months, and will not be complete until the tank if fully stocked. During this period, regular water testing and water changing will ensure that water quality never deteriorates to dangerous levels.
Stocking
Although the actual number of fish that can be housed depends on a number of factors, the following recommendations are a good rule of thumb:
Tropical tanks: 1in per 10in2 (1cm per 25cm2)
Coldwater tanks 1in per 30in2(1cm per 75cm 2)
For example, the number of fish you could have in a 2ft by 1ft Tropical tank would be: (24in x 12in) divided by 10in = 29in of fish
When buying fish it is important to remember the maximum size they will grow to. Fish will not necessarily grow to the size of the tank, and in cases where they do it is usually because they are in an unsuitable environment. If you wish to increase the number of fish that you have, thenyou may need to increase the filter size, add additional aeration, and increase the frequency of water changes (although advice should be sought before doing this).
Feeding
Community aquarium fish and goldfish should be fed once or twice a day with a good quality fish food (Aquarian Flakes or TetraMin Complete for instance). They only need a small amount and should have consumed it within a couple of minutes. Any uneaten food should be removed from the tank immediately. Overfeeding your fish will result in poor water quality as more ammonia is produced, and oxygen is used up. Some fish, such as certain species of catfish and loach are nocturnal an will not come out for food until after the aquarium lights have been switched off. Tetra TabiMin is a good tablet food that will suit a range of species, whereas Hikare Algae Wafers are ideal for some of the algae-eating varieties of catfish. If you are going away on holiday, then there are special food, (such as tetra Holiday Food) that may be added to the tank before you leave. These will break dfdown ovwer a week or so, providing your fish with food whilst you are away. It is a good idea to give your fish frozen food once or twice a week, as they particularly enjoy it and it provides them with many essential nutrients. There are many different varieties of frozen food available, e.g. daphnia, bloodworm, krill, cockles, brine shrimp etc.
Maintenance
Once the tank if fully stocked and the filter has matured, it should be possible to reduce the frequency of water changes. This is because the filter should be removing all of the ammonia and nitrite from the water, and so it is only the nitrate that is building up. Whilst this is fairly harmless, it still needs to be kept under control, as high levels may stress the fish, and will encourage the growth of algae. Phosphate will also start to build up in the tank (as it is present in the fish food and is therefore excreted by the fish) which can further encourage the growth of algae. Changing part of the water on a regular basis will help to keep the levels of these substances under control. Ideally a third of the water should be replaced once every two weeks. When carrying out a water change, follow these guidelines:
1. Fill up a bucket with the required amount of tap water and treat it with a dechlorinator (such as Stress Coat). The dechlorinator will neutralise any chlorine in the tap water that would otherwise damage the fishes’ gills. Hot water from the kettle may be added to the bucket to try and match the temperature of the tank (never use water from the hot tap).
2. Turn the electrics to the tank off and take out any large objects, then leave the tank for around twenty minutes to allow the heater to cool down.
3. A third of the water can then be siphoned out of the tank. It is a good idea to use an attachment for cleaning the gravel when doing this, as it will allow you to remove debris trapped in the substrate. Clean gravel will result in a much healthier environment for the fish.
4. When the water has been removed you can replace it with the prepared tap water, either siphoning it into the tank or using a jug. The electrics can then be turned back on, but the light should be left off for the rest of the day, in order to allow the fish to settle down again.
It is a good idea not to feed the fish the day before a water change is carried out, and do not feed them again until the day after. If you are not using a gravel cleaner, or if the tank is difficult to clean, then it will be necessary to carry out large clean-outs from time to time (see staff for advice).
Monitoring Water Quality
Even after the filter has matured, we recommend that you test the quality of your tank water at least once a week. Water quality may deteriorate in the tank for a number of reasons, including overfeeding, inadequate filtration or oxygenation (as the fish grow they produce more ammonia and use up more oxygen), reduction in filter performance due to the use of disease treatments, mishandling of the filter, the build-up of waste on the gravel, and so on. Although the fish may not exhibit any obvious signs of distress, poor water quality will result in them being permanently “stressed”. When fish are stressed they release hormones into the blood which have the effect of reducing the efficiency of their immune systems, resulting in them becoming more susceptible to disease. Occasional fish losses are often attributable to poor water quality, as some fish are more sensitive than others. It is therefore essential that the water is regularly testes for ammonia and nitrite, and ideally pH and nitrate as well. This will let you know if your filter is working properly, and if you are maintaining the tank correctly. The best time to test the water is 3 – 5 hours after feeding the fish (a few days before you do a water change), and also just before you carry out a water change.
